samples: drivers: crc: add samples for CRC driver

Add samples for CRC driver

Signed-off-by: Duy Vo <duy.vo.xc@bp.renesas.com>

Author: Duy Vo

samples/drivers/crc/CMakeLists.txt

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+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(driver_crc_example)
+
+target_sources(app PRIVATE src/main.c)

samples/drivers/crc/README.rst

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+.. zephyr:code-sample:: crc_drivers
+   :name: Cyclic Redundancy Check Drivers (CRC)
+   :relevant-api: crc_interface
+
+   Compute and verify a CRC checksum using the CRC driver API.
+
+Overview
+********
+
+This sample demonstrates how to use the :ref:`CRC driver API <crc_api>`.
+
+Configuration Options
+*********************
+
+This sample supports the following Kconfig options:
+
+- ``CONFIG_CRC_HW``: Enable CRC driver.
+
+These options can be modified in the project's ``prj.conf`` file or passed via CMake arguments.
+
+Building and Running
+********************
+
+Building and Running for Renesas RA8M1
+======================================
+
+The sample can be built and executed for the
+:zephyr:board:`ek_ra8m1` as follows:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/crc
+   :board: ek_ra8m1
+   :goals: build flash
+   :compact:
+
+To build for another board, change "ek_ra8m1" above to that board's name.
+
+Sample Output
+=============
+
+.. code-block:: console
+
+   crc_example: CRC verification succeed.
+
+.. note:: If the CRC is not supported, the output will be an error message.
+
+Expected Behavior
+*****************
+
+When the sample runs, it should:
+
+1. Compute the CRC8 values of predefined data.
+2. Verify the CRC result.

samples/drivers/crc/prj.conf

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+CONFIG_CRC_NEW=y
+CONFIG_CRC_LOG_LEVEL_INF=y
+CONFIG_LOG=y

samples/drivers/crc/sample.yaml

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+sample:
+  name: CRC Sample
+tests:
+  sample.drivers.crc:
+    depends_on: crc
+    tags:
+      - drivers
+      - crc
+    harness: console
+    harness_config:
+      type: one_line
+      regex:
+        - "CRC verification succeeded"

samples/drivers/crc/src/main.c

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+/*
+ * Copyright (c) 2025 Renesas Electronics Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(crc_example, CONFIG_LOG_DEFAULT_LEVEL);
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/crc.h>
+
+/* The devicetree node identifier for the "crc" */
+#define CRC_NODE DT_NODELABEL(crc)
+
+/*
+ * A build error on this line means your board is unsupported.
+ * See the sample documentation for information on how to fix this.
+ */
+
+int main(void)
+{
+	static const struct device *const dev = DEVICE_DT_GET(CRC_NODE);
+	/* Define the data to compute CRC */
+	uint8_t data[8] = {0x0A, 0x2B, 0x4C, 0x6D, 0x8E, 0x49, 0x00, 0xC4};
+	int ret;
+
+	if (!device_is_ready(dev)) {
+		LOG_ERR("Device is not ready");
+		return -ENODEV;
+	}
+
+	struct crc_ctx ctx = {
+		.type = CRC8,
+		.polynomial = CRC8_POLY,
+		.seed = CRC8_INIT_VAL,
+		.reversed = CRC_FLAG_REVERSE_OUTPUT | CRC_FLAG_REVERSE_INPUT,
+	};
+
+	/* Start CRC computation */
+	ret = crc_begin(dev, &ctx);
+
+	if (ret != 0) {
+		LOG_ERR("Failed to begin CRC: %d", ret);
+		return ret;
+	}
+
+	/* Update CRC computation */
+	ret = crc_update(dev, &ctx, data, 8);
+
+	if (ret != 0) {
+		LOG_ERR("Failed to update CRC: %d", ret);
+		return ret;
+	}
+
+	/* Finish CRC computation */
+	ret = crc_finish(dev, &ctx);
+
+	if (ret != 0) {
+		LOG_ERR("Failed to finish CRC: %d", ret);
+		return ret;
+	}
+	/* Verify CRC computation
+	 * (example expected value: 0xB2 with LSB, 0x4D with MSB bit order)
+	 */
+	if (ctx.reversed != (CRC_FLAG_REVERSE_OUTPUT | CRC_FLAG_REVERSE_INPUT)) {
+		ret = crc_verify(&ctx, 0x4D);
+
+		if (ret != 0) {
+			LOG_ERR("CRC verification failed: %d", ret);
+			return ret;
+		}
+	} else { /* Reversed is no reversed output */
+		ret = crc_verify(&ctx, 0xB2);
+
+		if (ret != 0) {
+			LOG_ERR("CRC verification failed: %d", ret);
+			return ret;
+		}
+	}
+
+	LOG_INF("CRC verification succeeded");
+
+	return 0;
+}